Conventionally, there is a luminaire as described in JP 2005-93196 A (hereinafter, referred to as “document 1”). The conventional example in the document 1 includes an illumination head (a light source device) in which one or more light-emitting elements are arbitrarily arranged, and a power supply device (a lighting device) that is configured to supply power to the illumination head.
Here, plural types of illumination heads are previously provided, which have different rated current values, depending on a difference between the numbers of light-emitting elements in the plural types of illumination heads. Any one of the plural types of illumination heads is selectively connected with the power supply device. The plural types of illumination heads include identification resistors. The respective identification resistors have resistance values corresponding to the rated current values of the plural types of the illumination heads.
The power supply device is configured to determine the type (a rated current value) of an illumination head connected with an output terminal of the power supply device by detecting a resistance value of an identification resistor of the connected illumination head, and adjust an output current according to the determination result.
That is, in the conventional example of the document 1, it is possible to light the light-emitting elements of each illumination head at its rated current, using a single power supply device, regardless of characteristics (the rated current values) of the illumination heads.
However, in the conventional example of the document 1, it is required to more enhance accuracy of detecting the resistance value of the identification resistor with increase in the number of the plural types of illumination heads (light source devices). Also, when light emission colors or color temperatures are different in addition to the rated current values as the characteristics of the plural types of illumination heads, it is hard to identify the type of the connected illumination head by only the resistance value of the identification resistor.